366 THE CAUSES OF THE 



XI 



to make an induction from ; you generalise the 

 facts, and you expect to find sourness in apples 

 where you get hardness and greenness. You found 

 upon that a general law, that all hard and green 

 apples are sour ; and that, so far as it goes, is a 

 perfect induction. Well, having got your natural 

 law in this way, when you are offered another 

 apple which you find is hard and green, you say, 

 &quot; All hard and green apples are sour ; this apple 

 is hard and green, therefore this apple is sour.&quot; 

 That train of reasoning is what logicians call a 

 syllogism, and has all its various parts and terms, 

 its major premiss, its minor premiss, and its 

 conclusion. And, by the help of further reason 

 ing, which, if drawn out, would have to be exhibited 

 in two or three other syllogisms, you arrive at your 

 final determination, &quot; I will not have that apple.&quot; 

 So that, you see, you have, in the first place, 

 established a law by induction, and upon that you 

 have founded a deduction, and reasoned out the 

 special conclusion of the particular case. Well 

 now, suppose, having got your law, that at some 

 time afterwards, you are discussing the qualities 

 of apples with a friend : you will say to him, &quot; It is 

 a very curious thing, but I find that all hard and 

 green apples are sour ! &quot; Your friend says to you, 

 &quot; But how do you know that ? &quot; You at once 

 reply, &quot; Oh, because I have tried them over and 

 over again, and have always found them to be so.&quot; 

 Well, if we were talking science instead of common 



